You may be right, I do know that there are very few total skydiving deaths per year so high risk activities could inflate the figures fairly easily. However, I don't think wing suiting is counted in the statistics.
It is if they exited a plane to do so.
I mean, based on the observations in the article, there's really no way to know the accident rate with any certainty. No one is even keeping track. It's all reliant on self-reporting to a lobbying organization that most these places aren't even a part of.